function change_page(page_name_robot, menu_id)
{
    //nastaveni promennych
    var max_id = 7;
    
    //zjisteni url
    base_path = "http://" + window.location.host;
    base_path = base_path + '/';
    
    //vlozeni loaderu
    document.getElementById('content').innerHTML = '<img src="'+base_path+'images/ajax-loader.gif" alt="Nahrávám..." class="loader">';

    //zjistime, zda jsme na sablone homepage a pokud ano smazeme class="mp"
    if(document.getElementById('content').className == 'mp')
    {
        document.getElementById('content').className = '';
    }
    
    //pokud preklikavame z aktivni stranky musime smazat tridu pro zvyrazneni hlavniho menu
    //pouzijeme funkci pro hledani pomoci nazvu tridy stylu z new_loader.js
    var menu = getElementsByClass('sel');
    //smazeme tridu tomuto prvku
    if(menu[0]) menu[0].className = '';
    
    
    //pokud nacteni probehne spravne nastavime odkaz jako aktivni
    if(menu_id)
    {
        //nejdrive nastavime vsechny tlacitka jako neaktivni
        var i=1;
        while(i<max_id)
        {
            var menu = 'menu'+i;
            var href = document.getElementById(menu);
            
            //vytahneme si nazev stranky
            var text = href.innerHTML;
            /*var text = text.split("<span>");
            var text = text[1].split("</span>");*/
            
            if($('#'+menu+' span').html().length > 15)
            {
                href.className = 'tile white tall';
            }
            else
            {
                href.className = 'tile white';
            }
            
            i=i+1;
        }
        
        //nastavime aktivni tlacitko
        if(page_name_robot.length > 15)
        {
            document.getElementById(menu_id).className = 'tile red tall';
        }
        else
        {
            document.getElementById(menu_id).className = 'tile red';
        }
        
        //nastavime sipky doleva a doprava
        var menu_index = menu_id.split('menu');
        
        var prev_id = parseInt(menu_index[1]) - 1;
        var next_id = parseInt(menu_index[1]) + 1;
        
        if(prev_id <= 0) prev_id = 1;
        if(next_id > max_id) prev_id = max_id - 2;
        
        
        var menu_prev = 'menu'+prev_id;
        
        var prev_href = document.getElementById(menu_prev).href;
        prev_href = prev_href.split("change_page('");
        prev_href = prev_href[1].split("', 'menu");
        prev_href = prev_href[0];
        
        if(document.all)
        {
          document.getElementById('larr').href = "javascript: change_page('"+prev_href+"', '"+menu_prev+"');";
        }
        else
        {
          document.getElementById('larr').href = "javascript: change_page('"+prev_href;
        }
        
        if(next_id >= max_id) next_id = max_id - 1;
        
        var menu_next = 'menu'+next_id;
        var next_href = document.getElementById(menu_next).href;
        next_href = next_href.split("change_page('");
        next_href = next_href[1].split("', 'menu");
        next_href = next_href[0];
        
        if(document.all)
        {
          document.getElementById('rarr').href = "javascript: change_page('"+next_href+"', '"+menu_next+"');";
        }
        else
        {
          document.getElementById('rarr').href = "javascript: change_page('"+next_href;
        }
        
       
    }
    //zavolame stranku change-page, kde je volan addon pro naceteni obsahu stranky a jako parametr page posleme name robot dane stranky
    $("#center_box").load(base_path+"change-page", { 'page': page_name_robot } );
    
     return;
}